A patient on antidiabetic therapy reports passing blood in urine for the past three days; which drug could cause this adverse effect?

• A. Metformin
• B. Pioglitazone
• C. Acarbose
• D. Exenatide

Answer: (B)

Hematuria signals a possible bladder or urinary tract issue. Among common antidiabetic agents, pioglitazone has been linked to an increased risk of bladder cancer with long-term use, and bladder pathology can present with blood in the urine. The other medications listed have different adverse effect profiles (metformin mainly GI upset and rare lactic acidosis; acarbose causes GI gas; exenatide can cause pancreatitis and GI symptoms) and are not associated with hematuria as a notable adverse effect. Therefore, pioglitazone is the drug most plausibly connected to this symptom. If this occurs, it warrants clinical evaluation for bladder pathology regardless of diabetes therapy.